Test ID: MBCR
BCR/ABL, Translocation 9;22, FISH (D-FISH)
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Establishing the percentage of neoplastic interphase nuclei for patients with chronic myeloid leukemia (CML) at diagnosis and at all times during treatment, even in cytogenetic remission
Detecting all known forms of the Philadelphia (Ph) chromosome
Identifying and monitoring of the Ph chromosome in patients with CML, acute lymphocytic leukemia (ALL), or acute myeloid leukemia (AML)
It is recommended that conventional chromosome analysis (BM/8506 Chromosome Analysis, for Hematologic Disorders, Bone Marrow) also be performed at initial diagnosis. Subsequently, D-FISH alone can be used to monitor the effectiveness of therapy.
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, if further probes are needed, they will be added at an additional charge.
The following algorithms are available in Special Instructions:
-Myeloproliferative Neoplasm: A Diagnostic Approach to Peripheral Blood Evaluation
-Myeloproliferative Neoplasm: A Diagnostic Approach to Bone Marrow Evaluation
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
Fluorescence In Situ Hybridization (FISH)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Abelson Oncogene
BCR Major and Minor Breakpoints
BCR-ABL, FISH
Breakpoints Cluster Region
Chromosome Analysis Consultation, Fluorescent In Situ Hybridization with BCR/ABL
Chronic Myeloid Leukemia
CML and ALL, BCR/ABL, FISH
FISH (Fluorescent In Situ Hybridization)
FISH, BCR/ABL Fusion
Fluorescence In Situ Hybridization (FISH) with BCR/ABL
Fluorescence In Situ Hybridization DNA Probes (D-FISH) with BCR/ABL
Fluorescent In Situ Hybridization (FISH)
Ph chromosome
Philadelphia Chromosome Ph1 Bone Marrow/Blood
t(9:22), FISH
BCR
ABL
ABL1
Acute Lymphoblastic Leukemia (ALL)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.
Forms:
1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
2. If not ordering electronically, submit a Cytogenetics Hematologic Disorders Request Form (Supply T607) with the specimen.
Advise Express Mail or equivalent if not on courier service.
Submit only 1 of the following specimens:
Specimen Type: Whole blood
Container/Tube: Green top (sodium heparin)
Specimen Volume: 7-10 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Other anticoagulants are not recommended and are harmful to the viability of the cells.
Specimen Type: Bone marrow
Container/Tube: Green top (sodium heparin)
Specimen Volume: 1-2 mL
Collection Instructions:
1. Invert several times to mix bone marrow.
2. Other anticoagulants are not recommended and are harmful to the viability of the cells.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Clotted blood or bone marrow |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Varies | Ambient (preferred) | |
| Refrigerated | ||
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
A proliferation of cells with a t(9;22)(q34;q11.2) occurs in the bone marrow and peripheral blood of more than 90% of patients with chronic myeloid leukemia (CML); in approximately 6% of children and 17% of adults with acute lymphoblastic leukemia (ALL); and approximately 1% of patients with acute myeloid leukemia (AML) with immature granulocytes.
The abnormal chromosome 22 derived from this translocation is called the Philadelphia (Ph) chromosome.
The remaining 10% of patients with CML have a variant Ph chromosome.
The classic Ph and all variants result in fusion of part of the Abelson (ABL1) oncogene from 9q34 with the breakpoint cluster region (BCR) at 22q11.2.
Conventional cytogenetic studies are widely used to quantify disease and to monitor the effectiveness of treatment for patients with CML; especially those on interferon or Gleevec/lmatinib mesylate therapy.
Considerable evidence shows a strong correlation between changes in percentage of Ph-positive metaphases after therapy and response to therapy.
The best outcome for survival and prolonged chronic phase appears to be in patients with CML in whom the percentage of Ph-positive metaphases is no longer detectable by conventional cytogenetics. When this happens, the patient is in cytogenetic remission.
This test offers a highly sensitive method using FISH and DNA probes for ABL1 and BCR for quantifying nonproliferating neoplastic cells with BCR and ABL1 fusion.
D-FISH (dual) ffusion FISH is a testing strategy that uses 2 fluorescent probes to identify and differentiate between the classic and variant Ph chromosomes by detecting double BCR and ABL1 fusion in cells with a t(9;22)(q34;q11.2): 1 on the abnormal chromosome 9 and 1 on the Ph chromosome.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
Specimens that contain > or =1% neoplastic nuclei with BCR and ABL1 fusion have a high likelihood of having a clone with t(9; 22) (q34; q11.2) or a variant of this anomaly.
Specimens with <1% interphase nuclei with BCR and ABL1 fusion may have minimal residual disease or do not have a neoplasm involving BCR and ABL1 fusion.
The normal range for interphase nuclei in blood and bone marrow is < or =5 cells when scoring between 500 and 6,000 nuclei. See Supportive Data.
D-FISH can detect >1% disease when 500 interphase nuclei are scored and >0.079% disease when 6,000 nuclei are scored.
To monitor the effectiveness of therapy, it is useful to divide the percentage of neoplastic cells after therapy by the percentage of neoplastic cells before treatment. Many clinicians use this calculation to classify the patient's response to therapy according to the table below.
| Cytogenetic Response to Therapy | Percent Neoplastic Nuclei Post-treatment Relative to Pretreatment |
| Absent | 100% |
| Minimal | 67%-99% |
| Minor | 33%-66% |
| Major | 1%-32% |
| Complete | 0% |
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Conventional cytogenetic analysis should be performed at initial diagnosis.
D-FISH does not detect cytogenetic or molecular genetic anomalies other than BCR and ABL1 fusion.
Some patients with chronic myeloid leukemia may have a chromosome abnormality that produces an atypical D-FISH pattern not consistent with classical BCR/ABL1 fusion. The sensitivity of D-FISH for these patients varies depending on the nature of the chromosome anomaly and has not been established. Special scoring criteria will be established by examining metaphases with D-FISH to quantify disease in these patients.
Supportive Data
D-FISH was tested in 2 investigations:
-In the first, we studied 65 bone marrow specimens from 35 normal subjects and from 30 patients with chronic myeloid leukemia (CML) or acute myeloid leukemia (ALL) with various kinds of Philadelphia (Ph) chromosomes. We also studied 37 bone marrow specimens collected from 10 patients before therapy and at least twice during therapy.
-In the second investigation, we studied 37 paired-sets of blood and bone marrow (collected within 24-96 hours of each other) from 10 patients before and after therapy. We studied 10 normal bone marrow specimens and 10 normal blood specimens.
For patients undergoing treatment, the results of D-FISH in blood and bone marrow correlated closely with quantitative chromosome analysis for bone marrow.
The percentage of neoplastic nuclei in blood was usually lower than in bone marrow, but changes in percentage of neoplastic nuclei tracked closely in response to therapy.
| Nuclei Analyzed | Abnormal Nuclei Cutoff | Percent Cutoff |
| 500 | >5 | 1.000% |
| 1,000 | >5 | 0.500% |
| 1,500 | >5 | 0.333% |
| 2,000 | >5 | 0.250% |
| 2,500 | >5 | 0.200% |
| 3,000 | >5 | 0.167% |
| 3,500 | >5 | 0.143% |
| 4,000 | >5 | 0.125% |
| 4,500 | >5 | 0.111% |
| 5,000 | >5 | 0.100% |
| 5,500 | >5 | 0.091% |
| 6,000 | >5 | 0.083% |
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Dewald GW, Wyatt WA, Silver RT: Atypical BCR and ABL D-FISH patterns in chronic myeloid leukemia and their possible role in therapy. Leuk Lymphoma 1999;34(5-6):481-491
2. Dewald GW, Juneau AL, Schad CR, Tefferi A: Cytogenetic and molecular genetic methods for diagnosis and treatment response in chronic granulocytic leukemia. Cancer Genet Cytogenet 1997;94:59-66
3. The Italian Cooperative Study Group on Chronic Myeloid Leukemia: Interferon alpha-2a as compared with conventional chemotherapy for the treatment of chronic myeloid leukemia. N Engl J Med 1994;330:820-825
4. Dewald GW: Interphase FISH studies for chronic myeloid leukemia. In Methods in Molecular Biology. Vol 204. Molecular Cytogenetics: Protocols and Applications. Edited by YS Fan. Totowa, NJ, Humana Press, USA, 2002 pp 311-342
Method Description Describes how the test is performed and provides a method-specific reference
D-FISH can be performed on 1 mL of bone marrow aspirate or 5 mL of blood collected in sodium heparin. DNA probes that map to and span the common breakpoints of the ABL1 oncogene at 9q34 and the BCR at 22q11.2 are hybridized to the chromosomes of cells from bone marrow or peripheral blood. These probes are visualized by fluorescent microscopy. Normal metaphase and interphase cells have 2 red signals signifying the hybridization of the ABL1 probe to both chromosomes 9 at band 9q34, and 2 green signals signifying the hybridization of the BCR probe to both chromosomes 22 at band 22q11.2. Cells with a t(9;22)(q34;q11.2) have 1 red signal from the normal chromosome 9 at 9q34 and 1 green signal from the normal chromosome 22 at 22q11.2. In the abnormal chromosomes, parts of the hybridization sites for each of these probes have translocated to the other chromosome. Thus, 2 signals representing a fusion of red and green signals are observed (D-FISH); 1 on the abnormal chromosome 9 and the other on the abnormal chromosome 22. A small percentage of normal interphase cells will appear to have fusion signals because of the coincidental juxtaposition of 9q34 and 22q11.2.(Dewald GW, Wyatt WA, Juneau Al, et al: Highly sensitive fluorescence in situ hybridization method to detect double BCR/ABL fusion and monitor response to therapy in chronic myeloid leukemia. Blood 1998;91:3357-3365; Buno I, Wyatt WA, Zinsmeister AR, et al: A special fluorescent in situ hybridization technique to study peripheral blood and assess the effectiveness of interferon therapy in chronic myeloid leukemia. Blood 1998;92:2315-2321)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
88271 x 2-DNA probe, each
88275 x 2-Interphase in situ hybridization
88291-Interpretation and report
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| 16200 | Specimen | 31208-2 |
| 16340 | Specimen ID | N/A |
| G_511 | Source | N/A |
| 16201 | Order Date | N/A |
| G_514 | Reason For Referral | 42349-1 |
| 16202 | Method | In Process |
| 16204 | Results | 51867-0 |
| 16205 | Interpretation | 69965-2 |
| 16206 | Amendment | In Process |
| 16207 | Consultant | N/A |
| 16208 | Report Date | N/A |
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